The world's millionaires, who represent the top 1 percent of the population, now own a record 45 percent of the global wealth and their share is growing, according to a new report.

There are now 17.9 million households in the world, up 8 percent from 16.6 million last year, according to a report from The Boston Consulting Group. The U.S. has the most millionaires, with over 7 million millionaire households, with China ranking second with 2.1 million.

BCG's findings come as the bulls have run wild on Wall Street, sending stocks to new records. The firm noted that the "outlook remains very positive, but highly dependent on future performance of equities."

The world's millionaires own over $75 trillion in wealth, or 45 percent of the $167 trillion in total personal wealth in the world, according to the report. Their share is up from 44 percent in 2015.

By 2021, the world's millionaires will control $115 trillion in wealth, or 51 percent of the world total, according to the report.

"An increasing share of wealth is being held by millionaire households," according to the report.

Multimillionaires will see the strongest growth. Those worth $20 million to $100 million will see their wealth grow 8.4 percent a year through 2021, according to the report. Those worth more than $20 million will own more than a fifth of the world's wealth.